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Re: contact spark gap VSVFSQ



Original poster: "Jonathan Peakall" <jpeakall@xxxxxxxxxxxx>

Back when Gary was posting about the VSVFSG I was thinking of building a
rotary. I saw Gary's posts about the vac gap and built one of those instead.
I was running a fairly low powered TC, using a 15/120 NST. It worked like a
charm. My streamer length increased greatly. Since I never did build the
rotary, I can't say it is better, but it was dirt simple to build.

You can see the gap at: http://madlabs.info/spark_gaps.shtml

Jonathan
www.madlabs.info

----------------------------------------------------------------------
Some people are like a Slinky .. not really good for anything,
but you still can't help but smile when you shove them down the stairs.
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----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Saturday, April 14, 2007 6:20 PM
Subject: Re: contact spark gap VSVFSQ


> Original poster: gary350@xxxxxxxxxxxxx
>
> I posted this about 6 or 7 years ago here goes again.  Build yourself
> a VSVFSQ, Variable Speed Vaccuum Fan Spark Gap it works just as well
> as a rotory spark gap and it is much easier to build and costs
> less.  I built my first rotor many years ago rotated the motor to
> sink the gap got is adjusted for max output and it was working
> great.  Later I built a VSVFSQ and found it worked just as well as
> the rotor.  I posted the info here and Rickard Hull once said a rotor
> is just a fancy toy a well tuned spark gap works just a well. The
> VSVFSQ can be used on any size TC from 400 watts to 15KW.  It is
> nothing but an RQ gap with a vaccuum fan and a variac.  The cool
> thing about the VSVFSQ is you can turn the variac and watch the
> streamers get longer and shorter as you make adjustments.  A streamer
> can increase in length by 30% just by changing the fan speed.  The
> attached link shows my first VSVFSQ.  I have several of these I later
> discovered the air slots in the side are not needed.  It actually
> works fine just to let the fan suck air in the end of the 4" PVC pipe
> and over the gaps. Get you a $2.00 vaccuum cleaner at a yard sale or
> salvation army store remove the fan motor and build one.  As I recall
> I bought 6 fans from H&H for $10.00 each about 7 years ago.
>
>
http://s43.photobucket.com/albums/e358/gary350/?action=view&current=gap-1.jp
g
>
>
http://s43.photobucket.com/albums/e358/gary350/?action=view&current=gap-2.jp
g
>
> -----Original Message-----
>  >From: Tesla list <tesla@xxxxxxxxxx>
>  >Sent: Apr 13, 2007 11:49 PM
>  >To: tesla@xxxxxxxxxx
>  >Subject: contact spark gap
>  >
>  >Original poster: "Scott Bogard" <teslas-intern@xxxxxxxxxxx>
>  >
>  >Hi everybody.
>  >     Since everybody is talking about spark gaps, I figured I'd throw
>  >out an idea I've had rolling around in my head for a while.  A spark
>  >gap has losses in the spark, but solid state cannot handle the raw
>  >power a spark can (not yet anyway), so what if we eliminate the
>  >losses by having direct contact, and eliminate the power issue by
>  >dumping the semiconductors?  Here is my idea, take a rotary spark
>  >gap, and cut the disk mounted electrodes flush with the disk surface,
>  >then mount brass bushings between two shafts, pinching the disk
>  >between them.  As the disk turns it will make contact with the
>  >bushings and complete the tank circuit, dumping loads of power into
>  >the primary.  The obvious problem with this is it will arc before it
>  >rolls over the contact defeating the whole purpose, but my thinking
>  >is you could use a smaller rod to increase "quenching" and submerge
>  >the whole thing in mineral oil to keep stuff cool and cut down on
>  >spark, but you will need a really tough motor.  Has anybody out there
>  >tried this already?  would there be any benefit?  would it be as
>  >difficult to build as I think it would be?  Just curious, thank you
much.
>  >Scott Bogard.
>  >
>  >_________________________________________________________________
>  >MSN is giving away a trip to Vegas to see Elton John.  Enter to win
>  >today. http://msnconcertcontest.com?icid-nceltontagline
>  >
>  >
>  >
>  >
>
>
>